Lambert's Bay Tues 3 Sept 2019, 13:00

Lambert's Bay Tues 3 Sept 2019, 13:00
From weather report: T=23 deg C and RH=41%. 
For all the following calculations the atmospheric pressure is assumed to be 101.325 kPa and the efficiency of evaporative cooling is 30% ( see https://en.wikipedia.org/wiki/Evaporative_cooler#Performance ):
With evaporative cooling of 30% efficiency the air will be cooled to 20.59 deg C. 
RH after evaporative cooling will be 54.08%. 
Volumetric heat capacity of air before cooling is 1.2026 kJ/(m^3.degC)
Using Espy's equation for lifted condensation (LCL):
LCL before evaporative cooling is 1744 m
LCL after evaporative cooling is 1200 m.
The mass of water required to do the evaporative cooling is 1181 tonnes per cubic km.
Dew Point:
Dew point before evaporative cooling is 9.05 deg C
Dew point after evaporative cooling is 10.98 deg C
Danger of fire. The greater the Chandler Burning Index the greater the danger of fire:
Before evaporative cooling: Chandler burning index is 32.86 (fire is unlikely)
After evaporative cooling: Chandler burning index is 14.62 (fire is unlikely)
Saturated adiabatic lapse rate (SALR):
Before evaporative cooling initial SALR is 5.36 deg C per km rise.
After evaporative cooling initial SALR is 5.17 deg C per km rise.
Absolute humidity:
Before evaporative cooling the absolute humidity is 8.43 grams of water vapour per cubic metre.
After evaporative cooling the absolute humidity is 9.67 grams of water vapour per cubic metre.
Discomfort Index (DI). Above 110 is hazardous to health.:
Before evaporative cooling the DI is 79.4
After evaporative cooling the DI is 76.3
Water from air from condensation by cooling air:
Before evaporative cooling you can get 0.38 kg of water per kWh of cooling
After evaporative cooling you can get 0.49 kg of water per kWh of cooling
Vapour pressure deficit (VPD). Usually VPD should be between 0.45 kPa and 1.25 kPa:
Before evaporative cooling VPD is 1.66 kPa
After evaporative cooling VPD is 1.11 kPa